Audio problem: In the scene where Lucy first enters Peter's hospital room, you can hear a respirator, and he is not hooked up to one. Also, the respirator noise is much faster than an unconscious human should be breathing.
When Lucy and Jack are walking along the river, a long shot shows them approaching a lamppost with a kissing couple. In the next shot, they pass the lamppost but there is no one there. They finally pass the couple at the next lamppost.